Image information may be transmitted from a one device to another device via a communication network. For example, a Personal Computer (PC) might send a stream of video images to a viewer at a remote PC via the Internet. Because the rate at which image information can be transmitted may be limited (e.g., by a PC's modem), it may be desirable to reduce the amount information that needs to be transmitted. Moreover, it may be desirable to reduce the amount of information without degrading the quality of the image to an unacceptable degree.